Werner E R, Werner-Felmayer G, Wachter H
Institut für Medizinische Chemie and Piechemic, Universität Innsbuck, Austria.
J Chromatogr B Biomed Appl. 1996 Sep 20;684(1-2):51-8. doi: 10.1016/0378-4347(95)00507-2.
Tetrahydrobiopterin is a cofactor in hydroxylation reactions, including phenylalanine 4-monooxygenase, tyrosine 3-monooxygenase, tryptophan 5-monooxygenase, alkyl glycol ether monooxygenase and nitric oxide synthase. Determination of its biosynthesis is carried out to diagnose inherited diseases leading to partial defects in tetrahydrobiopterin synthesis. In addition, tetrahydrobiopterin synthesis is induced by proinflammatory cytokines, and intracellular levels of tetrahydro-biopterin in many cases limit the activity of tetrahydrobiopterin-dependent reactions, such as nitric oxide synthase in intact cells. Biosynthesis of tetrahydrobiopterin from guanosine 5'-triphosphate (GTP) requires the action of three enzymes, GTP-cyclohydrolase I (E.C. 3.5.4.16), 6-pyruvoyl tetrahydropterin synthase (EC, 4.6.1.10) and sepiapterin reductase (E.C. 1.1.1.153). Methods for quantification of biopterin and related pteridines in biological matrices by HPLC and application of these for determining the activity of the three tetrahydrobiopterin biosynthetic enzymes are reviewed in this article.
四氢生物蝶呤是羟化反应中的一种辅助因子，包括苯丙氨酸4-单加氧酶、酪氨酸3-单加氧酶、色氨酸5-单加氧酶、烷基二醇醚单加氧酶和一氧化氮合酶。对其生物合成进行测定以诊断导致四氢生物蝶呤合成部分缺陷的遗传性疾病。此外，促炎细胞因子可诱导四氢生物蝶呤的合成，并且在许多情况下，细胞内四氢生物蝶呤的水平会限制四氢生物蝶呤依赖性反应的活性，如完整细胞中的一氧化氮合酶。从鸟苷5'-三磷酸（GTP）合成四氢生物蝶呤需要三种酶的作用，即GTP环化水解酶I（E.C. 3.5.4.16）、6-丙酮酰四氢蝶呤合酶（EC, 4.6.1.10）和蝶啶还原酶（E.C. 1.1.1.153）。本文综述了通过高效液相色谱法对生物基质中的生物蝶呤和相关蝶啶进行定量的方法，以及将这些方法应用于测定三种四氢生物蝶呤生物合成酶活性的情况。
